Nondestructive Detection of Sunflower Seed Vigor and Moisture Content Based on Hyperspectral Imaging and Chemometrics.

Sunflower is an important crop, and the vitality and moisture content of sunflower seeds have an important influence on the sunflower's planting and yield. By employing hyperspectral technology, the spectral characteristics of sunflower seeds within the wavelength range of 384-1034 nm were carefully analyzed with the aim of achieving effective prediction of seed vitality and moisture content. Firstly, the original hyperspectral data were subjected to preprocessing techniques such as Savitzky-Golay smoothing, standard normal variable correction (SNV), and multiplicative scatter correction (MSC) to effectively reduce noise interference, ensuring the accuracy and reliability of the data. Subsequently, principal component analysis (PCA), extreme gradient boosting (XGBoost), and stacked autoencoders (SAE) were utilized to extract key feature bands, enhancing the interpretability and predictive performance of the data. During the modeling phase, random forests (RFs) and LightGBM algorithms were separately employed to construct classification models for seed vitality and prediction models for moisture content. The experimental results demonstrated that the SG-SAE-LightGBM model exhibited outstanding performance in the classification task of sunflower seed vitality, achieving an accuracy rate of 98.65%. Meanwhile, the SNV-XGBoost-LightGBM model showed remarkable achievement in moisture content prediction, with a coefficient of determination (R2) of 0.9715 and root mean square error (RMSE) of 0.8349. In conclusion, this study confirms that the fusion of hyperspectral technology and multivariate data analysis algorithms enables the accurate and rapid assessment of sunflower seed vitality and moisture content, providing robust tools and theoretical support for seed quality evaluation and agricultural production practices. Furthermore, this research not only expands the application of hyperspectral technology in unraveling the intrinsic vitality characteristics of sunflower seeds but also possesses significant theoretical and practical value.

Exploring the potential of open big data from ticketing websites to characterize travel patterns within the Chinese high-speed rail system.

Big data have contributed to deepen our understanding in regards to many human systems, particularly human mobility patterns and the structure and functioning of transportation systems. Resonating the recent call for 'open big data,' big data from various sources on a range of scales have become increasingly accessible to the public. However, open big data relevant to travelers within public transit tools remain scarce, hindering any further in-depth study on human mobility patterns. Here, we explore ticketing-website derived data that are publically available but have been largely neglected. We demonstrate the power, potential and limitations of this open big data, using the Chinese high-speed rail (HSR) system as an example. Using an application programming interface, we automatically collected the data on the remaining tickets (RTD) for scheduled trains at the last second before departure in order to retrieve information on unused transit capacity, occupancy rate of trains, and passenger flux at stations. We show that this information is highly useful in characterizing the spatiotemporal patterns of traveling behaviors on the Chinese HSR, such as weekend traveling behavior, imbalanced commuting behavior, and station functionality. Our work facilitates the understanding of human traveling patterns along the Chinese HSR, and the functionality of the largest HSR system in the world. We expect our work to attract attention regarding this unique open big data source for the study of analogous transportation systems.

[Experimental study on mechanism of recompression therapy of decompression sickness].

OBJECTIVE: To elucidate that recompression is the most efficient measure in removing the pathogenic factors. METHOD: When rabbits were suffering from severe DCS, their pressure were immediately compressed to 0.5 Mpa. Precordial region was monitored continuously with a Doppler flow meter, micrography of the bulbar conjunctiva was done intermittently and the behaviors of the animals were recorded. RESULT: Effects of therapeutic recompression and elimination of circulating bubbles were correlated to rate and extent of recovery of microvascular function. The animals' DCS with severe dysfunction or failure of blood vessels, DCS became worse owing to progressive impairment of microvascular function during recompression and decompression. CONCLUSION: The pressure could only cancel the tension provoked by supersaturated gas in the blood so as to relieve the spasm of the compensatory blood vessels, which can restore the blood circulation and reverse the developing course of the DCS. The pressure, however, couldn't recover the function of the blood vessels with severe dysfunction or failure, or repair the injured tissues, or eliminate the circulating bubbles directly.

[A study on etiology and pathogenic mechanism of decompression sickness].

OBJECTIVE: To explain the etiology of decompression sickness (DCS) and to elucidate its pathogenic mechanism. METHOD: Tunica conjunctiva was examined by microscopy and blood pressure was measured at the exposed femoral arteries in inadequately decompressed animals after hyperbaric exposure. Then pathological examinations were done. RESULT: Animals with vascular spasm and dysfunction after decompression showed DCS symptoms. Severe DCS was found in the period of increasing of blood pressure swelling. Appeared in endothelial cells, fracted, hemorrhages were also formed in the body of DCS animals. CONCLUSION: DCS is a disease with vascular spasm and dysfunction caused by decompression. It's resulted from anoxia or pathological change caused by vascular spasm, dysfunction or even failure of blood vessels due to the gas tension (etiology) provoked by supersaturated gas in the blood during descending of ambient pressure. Vascular spasm and dysfunction impede the elimination of gas from the blood, and once the gas amount is sufficient to cause severe ischemia of the circulation system, the state of disease would be severe.